Injection lance for uniformly injecting a steam/ammonia mixture into a fossil fuel combustion stream

A combination comprising:

• a furnace or combustion process having a flue gas stream moving therethrough;
• an outer tube having closed inner and outer ends;
• an inner tube centrally positioned in said outer tube, said inner tube having inner and outer ends, said inner end of said inner tube being open, said inner end of said inner tube being spaced apart from said inner end of said outer tube, said inner tube being in fluid communication with a feed mixture;
• an interior surface of said outer tube and an exterior surface of said inner tube forming an annulus for defining a first passageway;
• an interior surface of said inner tube defining a second passageway between said annulus and an interior of said inner tube through said open inner end of said inner tube;
• and
• at least one discharge orifice port extending from the interior surface of said inner tube to the exterior surface of said outer tube,
• wherein said feed mixture passes from said outer end of said inner tube towards said inner end of said outer tube in said first passageway and then passes into said interior of said inner tube in said second passageway and is discharged from said discharge ports.

A method for uniformly injecting a feed stream into a fuel combustion stream comprising the steps of:

• mixing steam with ammonia to form said feed stream;
• introducing said feed stream into an injection lance, said injection lance comprising an outer tube having closed inner and outer ends;
• an inner tube centrally positioned in said outer tube, said inner tube having inner and outer ends, said inner end of said inner tube being open, said inner end of said inner tube being spaced apart from said inner end of said outer tube said inner tube being in fluid communication with said feed mixture;
• an interior surface of said outer tube and an exterior surface of said inner tube forming an annulus for defining a first passageway;
• an interior surface of said inner tube defining a second passageway between said annulus and an interior of said inner tube through said open inner end of said inner tube;
• and at least one discharge orifice port extending from the interior surface of said inner tube to the exterior surface of said outer tube, said feed mixture passes from said outer end of said inner tube towards said inner end of said outer tube in said first passageway and then passes into said interior of said inner tube in said second passageway;
• and
• discharging said feed stream from said discharge ports into said fossil fuel combustion stream.